#
# Copyright (c) 2001-2004 Jakub Jermar
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# modification, are permitted provided that the following conditions
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#include <kernel/arch/context_offset.h>

.text

.global context_save
.global context_restore


## Save current CPU context
#
# Save CPU context to the context_t variable
# pointed by the 1st argument. Returns 1 in EAX.
#
context_save:
	movl 0(%esp),%eax	# the caller's return %eip
	movl 4(%esp),%edx	# address of the context variable to save context to

		# save registers to the context structure
	CONTEXT_SAVE_ARCH_CORE %edx %eax

	# Save TLS
	movl %gs:0, %eax
	movl %eax, OFFSET_TLS(%edx)     # tls -> ctx->tls
	
	xorl %eax,%eax		# context_save returns 1
	incl %eax
	ret


## Restore saved CPU context
#
# Restore CPU context from context_t variable
# pointed by the 1st argument. Returns 0 in EAX.
#
context_restore:
	movl 4(%esp),%eax	# address of the context variable to restore context from

		# restore registers from the context structure
	CONTEXT_RESTORE_ARCH_CORE %eax %edx

	movl %edx,0(%esp)	# ctx->pc -> saver's return %eip

	# Set thread local storage
	pushl %edx
	movl OFFSET_TLS(%eax), %edx   # Set arg1 to TLS addr
	movl $1, %eax         # Syscall SYS_TLS_SET
	int $0x30
	popl %edx
	
	xorl %eax,%eax		# context_restore returns 0
	ret